package collection;

import java.util.ArrayList;
import java.util.Collection;

public class CollectionDemo {
    public static void main(String[] args) {
        /*
        Collection c = new ArrayList();
        c.add(new Point(1,2));
        c.add(new Point(3,4));
        c.add(new Point(5,6));
        c.add(new Point(7,8));
        c.add(new Point(9,0));
        c.add(new Point(1,2));
        System.out.println(c);

        Point p = new Point(1,2);
        boolean contains = c.contains(p);
        System.out.println("是否包含:"+contains);

        c.remove(p);//若存在重复元素则只删除一次
        System.out.println(c);

         */

        //集合中存放的是元素的引用
        Collection cc = new ArrayList();
        Point pp = new Point(1,2);
        cc.add(pp);
        System.out.println("pp"+pp);
        System.out.println("cc"+cc);




















        /*
        Collection c = new ArrayList();
        c.add("one");
        c.add("two");
        c.add("three");
        c.add("four");
        c.add("five");
        System.out.println(c);
        System.out.println("size"+c.size());
        System.out.println("是否为空集"+c.isEmpty());

        c.clear();//清空集合
        System.out.println("集合已清空");
        System.out.println(c);
        System.out.println("size"+c.size());
        System.out.println("是否为空集:"+c.isEmpty());

         */

    }
}
